This invention relates to dynamoelectric machines and particularly to a brush cage for mounting commutator brushes in such a machine.
In the past, it has been common practice to mount the commutator brushes in a single brush cage mounted either on the motor end plate or on the motor frame around the commutator. In either case, it may be necessary to use excessively long leads from the brushes to the stator terminals to make the necessary connections before mounting the end plate. Alternatively, it may be necessary to provide access ports to the brushes, so that the electrical connections can be made after the plate is mounted. In multi-brush, small motors the limited available space can make these procedures quite difficult. A representative example of this particular approach is found in U.S. Pat. No. 3,510,709. Moreover, mounting the brush cage in this manner is disadvantageous in that it complicates machine assembly and inhibits the accessibility of the brushes and commutators for servicing and replacement. In addition, the bends and turns on the wires connecting the brushes and stator branches increase the effective brush resistance and deteriorate motor performance. Also, the access ports make it increasingly difficult and expensive to construct a water-tight motor housing around the commutator and brush cage.